I live from time to time on my motorboat (bought second hand, polyester and mahogany, former motorsailer, I removed mast and sails, 25 ft). And make slow travels with it. For heavy wintertime (I sail in Belgium, North Germany and Netherlands and its coastal waters) it is not insulated enough, so I use it from April till the beginning of December. Sometimes for 3 months in a row. But I could live on it for 10 month on a row if I wish. The initial investment was around € 15 k, the cost of renting (a) place(s) depends on your inventiveness, for me it is about € 0,5 k per year. Maintaining boat and its (diesel inboard) motor and two small batteries is DIY, its costs are about € 0,2 k per year. I have a fuel economic diesel motor, it uses 0,7 ltr per hour at a traveling speed of 7 km per hour. I can handle the boat alone, but sometimes my wife or friends accompany me. So (for me) costs are low, adventures are abundant.

@J_ Do you rent a fixed place for € 0.5k per year, or is that for multiple places? Here in Norway, it's allowed to anchor for free on public places (like islands in the fjords) as long as you move each second day. Do you have any possibilities for free anchoring there too?

@liberty: My fixed place (in the center of the town and on walking distance of my house) costs € 360 per year the rest, € 140, I pay for visiting marina's underway during my trips. And yes, like in your country I do also free anchoring on lakes, or use for free public places which I can often use for three days in a row as long as you move thereafter. But if I travel in April or September till December many marinas and town-canal places are for free because there are no harbormasters (and hardly any other motor/sail boats. I can always find a nice person who let me fill my two canisters with water. And diesel for the motor I buy at regular car-tank-stations which are often in walking distance from a canal. I have two 5 liter canisters for that purpose. I have a fixed Wallas boat-heater on kerosine for using my boat in chilly times. I have no other electric equipment like radar or a refrigerator on board, so I do not need electricity from quay-stations.The electricity for uploading the two boat-batteries and batteries of my handy, laptop and Marifoon, is suplied by the dynamo/generator during motoring.

I know a guy in my city who lives on a boat moored in a marina near the city.

The total cost for mooring plus live a board is about $1,000 per month for a 34 foot boat. That gives access to all the common facilities like showers, bbq area, big kitchen etc. Then he uses solar power and also a diesel system to heat the boat - which apparently is really cheap to run unlike normal heaters. Then you need to factor in the cost of buying a boat (otherwise investment income) and boat maintenance - no idea how much that is - I will need to ask him.

Essentially in my expensive city this works out cheaper than renting your own place but is more expensive than living in a room in a shared place (takin the boat purchase and maintenance into account). If you take the boat off marina though it would be WAY cheaper. But cant really do that if you work somewhere.

I have a relative who works full time on a sailboat, captaining people around the ocean on their vacation. His DH is the chef. I think they also scuba dive. I guess if you like being on the ocean, its a way to make a living.

I'm open to the idea but I love land. I also love swimming in gorgeous warm water but the idea doesn't have a huge appeal to me at this point. A van sounds more appealing as I feel drawn to being in cities at this time.

@slowtraveler - van living is appealing to me too and would be much cheaper. But main thing I think about is the likelihood of being harassed by people in your home - whereas a boat can very much give you a sense of much privacy - espeically when you moor it away from a marina when you are not working

This is my dream too (same as @funkychicken69 above). I'm still trying to convince my wife of this dream. We have a long way to go if we were to make this our reality. I think it would be an awesome way to see the world if you could take your time (perhaps 5-7 years at least). There is a lot of cruising sailer's books/blogs/forums to read and for now, for me, it's mild escapism. However, if you read enough, you start to also get a picture of how things can go wrong too or some of the potential downsides. I'm still convinced it would be amazing.

When we get done living in a vintage RV, we plan to pick up a (somewhat) vintage boat and restore it. But I would not even think of doing so as a way to save money or live cheaply, it's just something I want to do. There's pretty much nothing cheap about a boat. In my (limited) experience anyway.